1. Field of the Invention
The present invention relates generally to a passive humidification apparatus, and more specifically to a humidifier for a continuous positive airway pressure (CPAP) device.
2. Relevant Prior Art
CPAP devices are now commonly used to treat a variety of respiratory disorders, including sleep apnea. CPAP devices normally consist of an air pump connected to a mask worn by a patient while they are sleeping.
Although CPAP devices have been very successful in treating these disorders, there is at least one associated drawback. The air that is introduced into the patient""s respiratory system tends to have the effect of drying out mucous membranes. In order to mitigate this problem, several types of passive humidifiers have been developed that can be connected between the CPAP device and the associated mask without interfering with the normal operation of the device.
One such passive humidifier is disclosed in U.S. Pat. No. 5,231,979 to Rose et al. This humidifier consists mainly of a chamber having an inlet and an outlet and that is partially filled with water. In operation, the outlet of a CPAP device is connected to the inlet of the humidifier and the mask is connected to the outlet of the humidifier. When the air supplied by the CPAP device enters the humidifier chamber and passes over and contacts the water, some moisture is added to the air through evaporation before the air ultimately passes to the mask and into the patient. This humidifier, however, is very ineffective and normally produces insufficient levels of humidity.
To improve the efficacy of the passive humidification system, some such humidifiers have been provided with baffles located within the humidifier chamber. One such baffled humidifier is disclosed in U.S. Pat. No. 5,598,837 to Sirianne, Jr. et al. In this humidifier, air is made to flow around the baffles which increases its length of contact with the water and also tends to augment the evaporation process. However, this humidifier design still falls short of providing an optimum level of moisture in the output air. Additionally, the shape of this humidifier precludes most CPAP devices from resting on top of the humidifier, and thus it significantly increases the footprint of the CPAP system.
According to one aspect of the present invention, a humidifier for a continuous positive airway pressure device is provided. The humidifier comprises a humidifier body, an air inlet provided to the humidifier body, an air outlet provided to the humidifier body, and a plurality of chambers defined within the humidifier body. The humidifier further comprises a plurality of baffles between one of the plurality of chambers and an adjacent one of the plurality of chambers, an opening provided between two of the plurality of baffles, the opening connecting the adjacent two of said plurality of chambers, and a deflector baffle being one of the plurality of baffles, the deflector baffle being located proximate to the opening and defining a serpentine fluid flow path between the adjacent chambers.
According to another aspect of the present invention, a humidifier comprises a non-planar dividing wall separating an adjacent two of said plurality of chambers, and an opening in the dividing wall providing fluid communication between chambers.
According to a further aspect of the present invention, a humidifier comprises a base, a cover having a resilient peripheral portion removably securing the cover to the base, a chamber defined by the base and cover, an inlet in communication with the chamber, and an outlet in communication with the chamber.